In situ remediation of ortho-nitrochlorobenzene in soil by dual oxidants (hydrogen peroxide/persulfate)

The efficacies of catalyzed H 2 O 2 , activated persulfate, and catalyzed H 2 O 2 -persulfate processes for the degradation of ortho -nitrochlorobenzene ( o -NCB) in soil were investigated. The application of catalyzed H 2 O 2 -persulfate process was promising, and after a careful adjustment of oxidants and activator doses, it demonstrated a considerable improvement in o -NCB degradation compared with activated persulfate process and catalyzed H 2 O 2 process. The degradation of o -NCB in catalyzed H 2 O 2 -persulfate process was obviously influenced by the concentration of persulfate and H 2 O 2 , the molar ratio between persulfate and H 2 O 2 , the concentration of o -NCB, and initial pH. Degradation of o -NCB was obviously inhibited by the addition of tert -butyl alcohol, methanol, and phenol, suggesting that nitrobenzene was dominantly oxidized by HO· and SO 4 − · generated in the catalyzed H 2 O 2 -persulfate process. The results from these studies demonstrated that the natural iron species present in soil could effectively facilitate the degradation of organic pollutants in the presence of H 2 O 2 and persulfate.